It certainly doesn't - there are enough "cowboy" US operators who are working far below the quality and safety standards which are practiced by European contractors. It's really a struggle sometimes to ensure that things are done properly and safely in the US. It's a practically new industry in the US and there is a lot of catching up to do.
As the article says, there are currently no WTIV ships that meet the requirements of the Jones Act. So you can't really say the law guarantees something that doesn't exist.
The Jones Act has failed in every way.
B...b...but I want to monomaniacally focus on short-term market prices, like they're the only thing that matters in the world! Quit cramping my ideological fixation with complicating factors!